Textile printing apparatus



March 30, 1943.

s. a. STAFFORD 2 9 TEXTILE PRINTING APPARATUS Filed Odt. 24, 1,940

In In Zhwentor 515 62672 B. S/dfford 1739 Q a ttorneg Patented Mar. 30,1943 TEXTILE PRINTING APPARATUS Stephen B. Stafford, Oxford, Mass,assignor to Rice Barton Corporation, a corporation of I MassachusettsApplication October 24, 1940, Serial No. 362,502

4 Claims.

This invention relates to textile printing apparatus and particularly toapparatus which is arranged for feeding fabric to the printing machinecontinuously and under proper tension for the printing operation.

Fabric to be printed for use as dress goods and the like may varysomewhat in ts composition, texture and width. Hence, as the fabrictravels to the printing roll it may wander laterally and not maintain analignment with the edges of the engraved surface of the roll. It has,therefore, been customary for the engraved portion of the printing rollto be made somewhat narrower than thewidth of the fabric to be printedand thereby leave an unprinted selvedge on the fabric; whereas in somecases it is desirable to print to the edge of the fabric. To this end,the apparatus should be so constructed that the fabric tracks or staysfed continuously under'a uniform tension and at a controlled width. Inthe preferred construction, fabric is fed from a succession of supplyrolls through a scray or other suitable accumu lator and then through atentering device arranged to stretch the fabric to a uniform width andfinally through a tensioning device to the printing machine. Thetensioning device may comprise an electrical brake or other suitable inalignment with the engraved portion of the printing roll. This involvesbringing the fabric to a uniform width just prior to its entry to theprinting zone. It, moreover, is desirable that the fabric be fed to theprinting zone under a uniform tension, but owing to the variations inthe texture of the cloth special provisions must be made to provide thisuniform tension. It has been proposed to pass the cloth over a dancerroller mounted near the printing roll and to provide tension in thecloth by means of springs which support the dancer roll. These springstend-to vibrate under the impulses imparted by the rapidly moving fabricand so cause the roll to dance and thus vary the tension on the fabricand defeat the purpose of the device. It is therefore desirable toemploy a construction which positively holds the fabric under a uniformtension and prevents any material variation in that tension as thefabric enters the printing zone.

The primary object of this invention is to overcome these variousproblems and to provide a textile printing apparatus which will causethe fabric to be fed properly to the printing zone.

A further object is to provide an apparatus which insures that thefabric to be printed is held at a uniform width under a uniform tensionas it enters the printing zone.

Another object is to provide an apparatus whereby fabric may be fedcontinuously to the printing zone from a succession of supply rolls andthe printing conditions properly maintained withoutstopping the machinefor removal of a supply roll. Further objects will be apparent in thefollowing disclosure.

In accordance with this invention, I have provided a printing machine towhich the fabric is mechanism which is so constructed and arranged thatthe fabric is held between it and the printing roll under asubstantially uniform tension, both laterally and longitudinallythereof.

Referring to the drawings which show a preferred embodiment of thisinvention:

Fig. 1 is a somewhat diagrammatic elevational view of an apparatusembodying this invention;

Fig. 2 is a vertical elevation of the tentering frame;

Fig. 3 is an end elevation of the same and shows a simplified wiring forits control; and

Fig. 4 is a wiring diagram showing the speed synchronization of theprinting roll and the tensioning device.

The printing machine is here illustrated, for the sake of simplicity ofillustration, as comprising a single printing roll Ill, but this type ofmachine may be provided with a plurality of rolls for the purpose ofprinting difierent colors or portions of a design pattern on the fabric.Each printing roll is suitably mounted in accordance with the standardpractice on a mandrel I l supported in half bearings 12 carried on slideblocks l3 adjusted by means of the screw and handwheel l4 toward andfrom the backing cylinder l5, so that the fabric l6 may be held underproper pressure as it passes through the printing zone between thebacking cylinder and the printing roll. The backing cylinder iscustomarily mounted for free rotation under the frictional drive of theprinting roll. Each printing roll is in turn driven by means of a geari8 connected to'the printing roll mandrel which meshes with the largegear wheel I9 axially aligned with the cylinder IS. The large gear isdriven by a gear 20 which in turn is driven through a chain 2| andsprocket 22. The latter is mounted on the axle of and driven by asuitable electric motor 24, which is designated as P. M. on the wiringdiagram. A roll 30 of the fabric to be printed may be removably mountedon a portion of the framework of the machine.

In order that the fabric may be fed continuously to the printing zone,provision is made which permits the rear end of the fabric on that rollto be sewed to the leading end of another roll without stopping theprinter. A suitable apparatus as shown comprises a scray arranged toaccumulate a supply of fabric or cloth as received from the roll and tofeed the same forward to the printer as needed. This scray comprises anendless belt .32 of suitable construction and which may be, for example,made of a rubber strip reinforced by cross strips of wood. This scraybelt is arranged as illustrated to support a considerable amount of thefabric as it is being accumulated and fed forward. Variousconstructional features may be employed for the purpose. As illustrated,the endless scray belt 32 passes over two upper rollers 34 and 35 andaround two lower rollers 36 and 31 which are suitably mounted on themachine framework. The roller 35 is driven by means of a sprocket 3ifixed thereto and connected by a chain to a small sprocket 35, and thelatter is in turn driven by another sprocket 44 secured thereto andconnected by a chain 41 to a-sprocket 3.8 keyed on the shaft of themotor 40. A chain 42 passes from the sprocket 43, which isconnected torotate with the roller 35, and it drives another sprocket 45 affixed torotate the roller 34. These parts are so arranged as to drive theendless scray belt at a very slow speed relative to the speed of thefabric passing therethrough. The

cloth is drawn from the supply roll into the scray belt by means of apair of power driven rollers 48 and 49, the upper roller beingadjustable toward and from the lower one to permit stopping the end feedof the fabric when desired. These two rolls are positively rotated bymeans of a further chain 50 driven by a sprocket 5| affixed to rotatewith the sprocket 39 and be driven by the motor 40. The sprocket 5| isslightly larger than the gear 4| on the shaft of the roll 49 so that therollers 48 and 49, which feed the fabric to the scray, travel fasterthan the rollers 54 and 55 which remove the fabric from the scray. Hencethe fabric will accumulate on the traveling scray belt as it passesforward to the printing zone. A suitable folding apparatus (not shown)may be employed to fold the fabric into loops on the scray belt as it isdrawn from the supply roll.

The fabric that is positively withdrawn from the scray by the rollers 54and 55 is led to a tentering frame which is arranged to stretch thefabric and to guide the same into the printing zone. The tenteringapparatus may be of any suitable standard construction and need not bedescribed in detail. It is simply illustrated in Figs. 2 and 3 ascomprising two endless chains and BI which are arranged to grip theentering fabric and stretch the same as the fabric and chains traveltogether toward the printing zone. These endless chains are arranged totravel at an angle so as to provide a gradually widening throat, andthis angle may be adiustedif desired. Each of the two chains is arrangedto pass around a pair of wheels or pulleys G2 and 63. The wheels 52 aremounted on short vertical shafts 64 suitably supported on the framework,and the other wheels 63 are mounted on longer shafts 65, each of whichcarries at its lower end the worm gear 66. Suitable bearings areprovided for mounting and supporting the various parts. These two wormgears (Fig. 3) are in turn driven by the left and right hand worms G8which are carried on a drive shaft 59, and this drive shaft is driven bya suitable electric motor 10.

The endless chains BI and 62 comprise a series of clamps arranged togrip the fabric as it enters the tentering frame. These clamps may besultably constructed and, as illustrated somewhat diagrammatically, maycomprise U-shaped clips 12 on which are pivotally mounted the fingers13, the lower ends of which are weighted and arranged to lie normally incontact with the lower supporting portion of the clip or the fabriclying thereon. A circular cam 15 is arranged in axial alignment witheach of the shafts 54 and 65 and is of such size that as the upwardlyprojecting finger 13 of the locking clips approach the fabric receivingend of the frame, they are tipped by the cam so that the oncoming fabricmay enter into position beneath the locking fingers 13 and then be heldthereby when the fingers fall into position after they have passedbeyond the cam. Similarly, at the exit end of the frame, the fingers arepushed outwardly to release the fabric and permit it to travel to theprinting zone. These constructional features may be suitably constructedin accordance with standard apparatus on the market. The two endlessfabric stretching belts are fixed at or adjusted to such an angle thatthe fabricis automatically stretched as it passes through this tenteringframe to a width which is determined by the distance between the opposedclamping fingers of the two belts.

The tentering frame may also m moved laterally in order to track oralign the fabric with the engraved surface of the printing roll. This isaccomplished by any suitable construction, such as that illustrated inFigs. 2 and 3. This comprises two screws threaded into two blocks 8|which are mounted to move laterally the table 82 supporting the endlesstenter frame belts and their driving mechanism. The ends of the screw 80are suitably mounted in hearings on the framework 84, and one end ofeach screw is connected to a worm gear 85 which is driven by a worm 86.These two worms 85 are rotated in the same direction by an electricmotor 88 having its shaft suitably connected thereto. The motor 88 is ofthe reversible type so that the tenter frame may be moved to either sidedepending upon the direction of rotation of the motor.

A suitable mechanical feeler or an optical control mechanism may beemployed to control the operation of the motor 85 and cause the fabricto be adjusted automatically into a desired track. This controlmechanism may comprise a pair of pivoted feelers engaging the oppositeedges of the traveling cloth and connected to electrical switches whichcontrol the motor so that if the cloth moves toward the left, the tenterframe will be moved toward the right and vice versa, and thereby insurea proper tracking of the cloth. This control mechanism may be made ofany suitable construction as is understood by one skilled in the art. Asimplified wiring diagram is shown in Fig. 3 of the drawings. Theapparatus comprises photoelectric tubes A located at the point where thefabric passes into the printing zone. Beams of light are passedvertically to these tubes and serve to activate them and lower theirresistance to an electric current. This occurs when the moving fabricdoes not out off the beam. The current passes through one of two relaycoils B in a suitable electric circuit which are connected to actuatethe two way reversing switch C. The latter is held in a centralinoperative position by springs D when the light beam strikes both ofthe tubes A and the pull of their relay cores B on the switch is equalin the opposite directions. If the fabric edge cuts off the light to onetube A, then the associated relay core is not activated and the othercore pulls the switch over into one of its contact positions, where thecurrent rotates the motor 88 in such a direction as to move the fabricfar enough laterally to permit the beam of light to strike the tubeagain and cause the fabric to travel in the new path. The parts are solocated that a slight deviation of the fabric from proper registrationor alignment with the printing roll will cause one or the other relay tooperate and move the fabric laterally as required. The tentering framemay, if desired, be arranged in a fixed position without provision forlateral movement of the fabric. It

' is preferably located close to the printer so that the fabric will notwander materially as it travels between the two parts.

The positively driven printing roll and the associated backing cylinderdraw the cloth into the printing zone, and the cloth is preferablysmoothed out by a pair of spreaders 90 and Si having opposed helicalthreads and made. of standard construction which aresuitablyarranged andmonuted on the printing machine framework. The oppositely directedhelical threads are so arranged that as the fabric passes thereover, itis smoothed out and spread toward its outer edges. The fabric has beenstretched laterally by the tenter frame and the spreaders are merelysupplementary to insure that no change occurs in the lateral stretch ofthe cloth.

A primary feature of this invention involves coordinating the mechanismswhich move the fabric and providing the proper tension on the cloth asit enters the printing zone. This tension may be applied to the fabricby means of a tensioning device which, in the embodiment illustrated,comprises an electrical brake; but various types of mechanical orhydraulic devices may be employed for the purpose. The deviceillustrated comprises a pair of rolls 92 and 93 which grip the fabrictherebetween. These rollers are mounted on parallel axes and are gearedtogether and arranged to rotate at the same speed. They are connected bya chain and sprocket with a direct current motor 96 suitably mounted or.the framework for driving them. The motor 96, designated T. M. on thewiring diagram of Fig. 4, is a constant speed electric motor which isoverdriven by the fabric at a higher rate than its normal speed so thatit is forced to act as an electric generator and thus resist the forwardmovement of the cloth. Various types of electric motor-and wiringarrangements may be employed as will be readily understood by oneskilled in the electrical art. This electric motor is preferably adaptedto run at a constant speed with a constant load and to vary in torquedirectly with variations in the current input. The motor may beconstructed and connected so that it tends to drive the fabric at a rateof, say, 75% of that at which the printing machine draws the fabricforward. The motor initially aids in moving the fabric while the machineis being started up; but when the fabric is moving at full speed, themotor is overdriven and becomes a generator of electricity and soapplies a counter force which resists the forward movement of the cloth.The faster the cloth moves, the greater is this counter torque appliedby the motor generator to increase the tension on the cloth.

The tension motor has the same general characteristics as another motorwith which it is connected in parallel in a constant voltage D. C.

circuit, and this other motor is preferably the printing machine drivingmotor. -A suitable wiring diagram for these two motors is shown in Fig.4, and the arrangement of the apparatus will be apparent by reference tothe legend on the diagram. The direct current generator G. D. C. in thevariable voltage armature circuit is driven by a suitable constant speedmotor. -This serves to drive the direct current printer motor P. M. andthe direct current tension motor T. M. at constant speeds when thecurrent is held constant. An exciter EX develops a direct current ofconstant amperage for the shunt fields which control the speeds of thetwo motors and the direct current generator. A constant currentregulator of standard construction which mechanically interconnects thearmature circuit and the shunt field circuit serves to maintain aconstant current in theshunt field circuit, and this may be furtherregulated as desired by the variable rheostat R. Suitable mechanism maybe employed to start and stop the motors as illustrated in the diagram,and this may be of any standard construction and need not be heredescribed. By adjusting the rheostat R, the shunt field of the tensionmotor may be varied to change the speed of that motor and thereby varythe back pressure or the longitudinal tension on the fabric. After thisadjustment has been made, then that tension will remain uniform becauseof the constant current developed in the circuit. That is, if the speedof the printer motor remains uniform, then the'current in the shuntfield remains uniform and the tension on the fabric does not change.This construction may be as shown in my prior application Serial No.300,433 filed October 20, 1939, and various detailsof the mechanisms andconstructional features there illustrated may be also incorporated inthis machine, if desired.

It is also desirable to hold the cloth under longitudinal tension as itenters the tentering frame, and to this end I employ mechanism whichwill insure that the motor which drives the feed rollers for removingthe fabric from the scray will have its speed controlled to maintaintension on the fabric. The preferred construction comprises a dancerroll 98 (Fig. 1) which is mounted on the end of a swinging arm 99 whichis one arm of a bell crank lever. The otherarm I00 is the control leverof a rheostat, illustrated diagrammatically at ml. The fabric it inpassing from the rolls Stand 55 goes around an idler roll I02 and thenaround the dancer roll 98 and over an idler roll I03 and a further rollI04 which is located to align the cloth with the tentering frame. Therheostat |0I and associated electrical mechanisms are so arranged thatwhen the dancer roll 98 moves down under its own weight, as permitted bya too rapid feed of the fabric by the rolls 54 and '55, it will move therheostat control arm in such a direction as to increase the current tothe shunt field of the motor 40 and thereby cause the motor to slow downslightly. Likewise, when the fabric is fed too slowly by rolls 54 and55, the rheostat arm will move'up and speed up the motor 40 and cause itto feed the fabric forward at a slightly greater rate. It will,therefore, be seen that the printer motor 24 or P. M. gives a referencespeed for the other motors. The electrical brake resists the forwardmovement of the fabric to the printer just enough to maintain it under asuitable tension, and the tension between the electrical brake and thescray is maintained by the dancer roll 88 which controls the speed ofthe motor 40.

The construction as above described may be employed without the use of aback gray cloth, which is customarily employed to receive the ink fromthe printing roll where it overlaps the fabric. Since the alignment ortracking of the fabric with the printing roll may be carefully regulatedin accordance with the above description,

then that back gray cloth need not be employed.

the fabric may be continued without interrup tion as a succession offabric rolls 3!! is supplied to the machine. The fabric is fed forwardat a continuous and substantially uniform rate by the feed rolls 54 and55, which withdraw the fabric from the scray at a rate determined by therequirements of the tentering frame. This rate is governed by the dancerroll 98 and the rheostat control NH. The fabric travels through thetentering apparatus and is there stretched to a predetermined width, andthis stretching serves to vary the tension on the cloth. The rate offeed of the fabric through the tentering zone is synchronized with thefabric movement into the printer by suitable mechanism. If desired, theprinter motor may be employed to pull the fabric through the tenteringzone. After the fabric leaves the tentering frame, it is passed directlyto the printer under a controlled tension, as provided by the electricalbrake rolls 82-93 which is operated automatically in accordance with thespeed of the printer rolls ID. This tension is invariable, once it hasbeen adjusted by means of the rheostat R f Fig. 4). There are noresilient parts to vibrate .and the tension is not affected by changingconditions in the texture of the fabric. The driving motors supply thefabric as needed and the tension motor holds back on the moving clothwith a uniform resistance. Hence, the tension is uniform. If a givenprinter roll I0 is removed from the machine and replaced by another rollof a greater or lesser.

diameter, the electrical brake may be regulated to function inaccordance with the speed requirements of the printing press and causethe cloth to be delivered thereto under a substantially uniform anddesired regulatable tension. If the printing press is speeded up andcalls for more fabric, this demand is communicated through the dancerr011 98 to the electric motor Mi which supplies the fabric at thatrequire rate.

It will also be noted that the tentering frame or cloth stretching andguiding apparatus is lo-- printing zone so that it takes the fabric inits 76 shortened and laterally stretched condition and governs thetension of that fabric at the point of delivery to the printing roll.Hence, the width of the fabric is controlled so that it may be broughtinto substantial alignment with the printing roll, and at the same timethe fabric is held under a required longitudinal tension. This insuresthat the fabric will be smooth both laterally and longitudinally andthus be in a proper condition for the printing step. This constructionalso insures that the edge of the fabric will be in alignment with acertain portion'of the printing roll, 50 that for some types of fabricit is possible to print to the extreme edge thereof; or if desired, aselvedge may be left unprinted but with the line of printingsubstantially straight and uniform. Various other advantages will beapparent in the above disclosure.

It will now be appreciated that numerous modificatiohs may be made inthis construction and other apparatus employed therewith as desired byone skilled in the'art; hence the above disclosure is to be interpretedas illustrating the principles of this invention and a preferredembodiment thereof and not as limitations on the claims appended hereto.

I claim:

1. A textile printing apparatus comprising a printing machine having apower driven printing roll and a backing cylinder which draw the fabricforward at a given rate for the printing op eration, means providing asupply of fabric of non-controlled tension, a device for stretching thefabric to a uniform width, mechanism located between said device'and theprinting zone for holding the fabric under a substantially uniformtension as it enters the printing zone, driving mechanism for feedingthe fabric to the stretching device and means governed by movement of.the fabric which controls said driving mechanism and causes the fabricto be held under tension and to move at a controlled rate as it entersthe stretching device.

2. A textile printing apparatus comprising a printing machine having aprinting roll and driving means associated therewith for moving a stripof fabric into the printing zone, means providing a supply of fabric,'adevice for stretching the fabric to a predetermined width and deliveringit at a point close to the printing machine, driving mechanism forsupplying the fabric to said stretching device at a controlled rate andunder a given tension, mechanism controlled by the lateral wandering ofthe fabric while being stretched which guides it into substantially apredetermined path as it enters the printing machine, and meansassociated therewith which opposes the forward movement of the fabriccaused by said driving means and holds it under a substantially uniformtension as it enters the printing zone.

3. A textile printing apparatus comprising a printing roll and drivingmeans associated therewith for moving a strip of fabric into theprinting zone, means for supplying fabric continuously for the printingoperation, a tentering frame for stretching the fabric to apredetermined width and delivering it at a position close to theprinting zone, means for moving the frame laterally and causing thefabric to travel substantially in a predetermined path, and meansopposing the forward movement of the fabric caused bysaid driving meansfor holding the fabric delivered by the tentering frame under asubstantially uniform but variable tension as it enters-the printingzone. I

4. A textile printing apparatus comprising a printing machine havingdriving means associated therewith for moving a strip of fabric into theprinting zone, means providing a supply of fabric in a condition ofuncontrolled tension, at tentering frame for stretching the fabric to apredetermined width and delivering it at a position close to theprinting'zone, means controlled by the position of the traveling fabricfor moving the frame laterally and causing the fabric to travel insubstantially a predetermined path as it enters the printing zone,driving mechanism for feeding the fabric to the tcntering frame,mechanism controlled by the movement of the fabric which controls saiddriving mechanism and causes the fabric to be held under tension as itenters the tentering frame and automatically controlled mechanism whichopposes the forward movemcnt of the fabric caused by said driving meansand maintains the stretched and guided fabric under a predetermined andsubstantially uniform but variable longitudinal tension as it enters theprinting zone. Y.

STEPHEN'B. STAFFORD.

